Exhaust fans that vent into the roof
Victoria's ventilation standard for rentals, and why a fan ducted into the roof space is a problem even when it works.
In short: A rental's bathroom must have ventilation. A fan that blows into the roof space moves the moisture out of the room and into the ceiling.
The standard
The ventilation standard requires a bathroom, shower room, toilet and laundry to have a window, vent or exhaust fan that lets moist air out. A fan is the usual answer in newer homes, and where it discharges matters for the building.
What we see
On a May 2026 inspection in Dandenong North the bathroom exhaust ended in the roof space instead of outside, and the kitchen rangehood did the same. Steam and cooking vapour were going straight into the insulation.
Why it matters to a landlord
Moist air in a cold roof space condenses on the underside of the roof and the timbers, and mould follows. In the bathroom itself, sealant blackens and paint peels, which leads to a mould and damp complaint.
How we check it
We confirm each wet room has a window, vent or fan, and where the roof space is safe to enter, follow the duct to see where it ends.
The fix
Extend the duct to an external vent or eave outlet. It is a modest job for an electrician or ventilation installer.
Written by our local inspection team from work carried out in Clyde North. Licensed building practitioners, Building & Plumbing Commission registration CDB-U 53425.
